Beta cells in your pancreas are responsible for producing a polypeptide called insulin and shipping it out of the cell and into the blood. These cells probably have a lot of
A Golgi
B vesicles
C microtubules
D motor proteins
E all of these
The correct answer and explanation is:
Correct Answer: E) all of these
Explanation:
Beta cells in the pancreas are specialized cells whose main role is to produce and secrete the hormone insulin, a polypeptide that regulates blood glucose levels. To accomplish this, beta cells rely on a highly active internal machinery to synthesize, package, and export insulin. This involves the participation of multiple cellular components:
- Golgi Apparatus (A):
After insulin is synthesized in the rough endoplasmic reticulum (RER), it is transported to the Golgi apparatus, which further processes and modifies the insulin (like cleaving it from proinsulin) and packages it into vesicles. The Golgi plays a key role in sorting and directing the final product to the appropriate location—in this case, outside the cell. - Vesicles (B):
Insulin is stored in secretory vesicles after processing. When blood glucose levels rise, these vesicles fuse with the plasma membrane and release insulin into the bloodstream via exocytosis. - Microtubules (C):
These are part of the cytoskeleton and act as tracks along which vesicles are transported from the Golgi to the plasma membrane. They play a crucial role in vesicle trafficking within the cell. - Motor Proteins (D):
Proteins such as kinesin and dynein are motor proteins that “walk” along microtubules, carrying vesicles loaded with insulin to their destinations. They convert chemical energy into mechanical work, making transport efficient and directional.
Given the intense secretory function of beta cells, all of these components are essential and abundant in these cells. They work together to ensure the efficient production, processing, and release of insulin. Therefore, the correct answer is E) all of these.